Adhesive, elastomeric gel impregnating composition

Abstract

An improved capacitor roll with alternating film and foil layers is impregnated with an adhesive, elastomeric gel composition. The gel composition is a blend of a plasticizer, a polyol, a maleic anhydride that reacts with the polyol to form a polyester, and a catalyst for the reaction. The impregnant composition is introduced to the film and foil layers while still in a liquid form and then pressure is applied to aid with impregnation. The impregnant composition is cured to form the adhesive, elastomeric gel. Pressure is maintained during curing.

What is claimed is:  
     
       1. An impregnant blend for film and foil layers comprising: 
       a polyester formed by the reaction of a polyol with a maleic anhydride;  
       a catalyst for the reaction; and  
       a plasticizer.  
     
     
       2. An impregnant blend according to  claim 1  also comprising a crosslinking material to provide toughness to the impregnant. 
     
     
       3. An impregnant blend according to  claim 1  wherein the polyol is a polybutadiene diol that is present in the blend, before reaction, in a range of from about 8% to about 20% by weight of the blend. 
     
     
       4. An impregnant blend according to  claim 3  wherein the polyol is present in an amount of 13.3% by weight of the blend. 
     
     
       5. An impregnant blend according to  claim 1  wherein the maleic anhydride is present in the blend, before reaction, in a range of from about 10% to about 25% by weight of the blend. 
     
     
       6. An impregnant blend according to  claim 5  wherein the maleic anhydride is present in an amount of 16% by weight of the blend. 
     
     
       7. An impregnant blend according to  claim 1  wherein the plasticizer is di-butyl phthalate that is present in the blend in a range of from about 50% to about 80% by weight of the blend. 
     
     
       8. An impregnant blend according to  claim 7  wherein the plasticizer is present in an amount of 67.3% by weight of the blend. 
     
     
       9. An impregnant blend according to  claim 1  wherein the catalyst is DAMA 1010 that is present in the blend in a range of from about 0.1% to about 3% by weight of the blend. 
     
     
       10. An impregnant blend according to  claim 9  wherein the catalyst is present in an amount of 1% by weight of the blend. 
     
     
       11. An impregnant blend according to  claim 2  wherein the crosslinking material is Solvermol VP95 that is present in the blend in a range of from about 0% to about 4% by weight of the blend. 
     
     
       12. An impregnant blend according to  claim 11  wherein the crosslinking material is present in an amount of 2.4% by weight of the blend.